From 6f041e99fc7ba00e7e65a431527f9235d6b16463 Mon Sep 17 00:00:00 2001 From: James Hogan Date: Thu, 21 Nov 2013 13:44:14 +0000 Subject: [PATCH] of: Fix NULL dereference in unflatten_and_copy() Check whether initial_boot_params is NULL before dereferencing it in unflatten_and_copy_device_tree() for the case where no device tree is available but the arch can still boot to a minimal usable system without it. In this case also log a warning for when the kernel log buffer is obtainable. Signed-off-by: James Hogan Cc: Rob Herring Signed-off-by: Grant Likely --- drivers/of/fdt.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c index 2fa024b97c43..758b4f8b30b7 100644 --- a/drivers/of/fdt.c +++ b/drivers/of/fdt.c @@ -922,8 +922,16 @@ void __init unflatten_device_tree(void) */ void __init unflatten_and_copy_device_tree(void) { - int size = __be32_to_cpu(initial_boot_params->totalsize); - void *dt = early_init_dt_alloc_memory_arch(size, + int size; + void *dt; + + if (!initial_boot_params) { + pr_warn("No valid device tree found, continuing without\n"); + return; + } + + size = __be32_to_cpu(initial_boot_params->totalsize); + dt = early_init_dt_alloc_memory_arch(size, __alignof__(struct boot_param_header)); if (dt) { -- 2.20.1